TW201516573A - Positive resist composition and patterning process - Google Patents

Abstract

A positive resist composition is provided comprising a polymer comprising recurring units having a carboxyl and/or phenolic hydroxyl group substituted with an acid labile group and recurring units of tert-butyl or tert-amyl-substituted hydroxyphenyl methacrylate and having a weight average molecular weight of 1,000-500,000. The resist composition has a satisfactory effect of suppressing acid diffusion and a high resolution, and forms a pattern of good profile and minimal edge roughness after exposure.

Description

Positive photoresist material and pattern forming method using same

The present invention relates to a positive-type photoresist material and a pattern forming method using a polymer compound suitable as a positive-type photoresist material, particularly suitable as a base resin of a chemically amplified positive-type photoresist material.

With the increase in density and speed of LSI, the miniaturization of pattern rules is rapidly progressing. In particular, the expansion of the flash memory market and the increase in memory capacity have led to miniaturization. As a state-of-the-art micronization technology, mass production of 65 nm node elements has been carried out using argon fluoride lithography, and mass production of 45 nm nodes using argon fluoride immersion lithography is also underway for the next generation. As the 32nm node of the next generation, a liquid and high refractive index lens with a higher refractive index than water, a high refractive index photoresist film, a immersion lithography using a super high NA lens, and a vacuum ultraviolet light having a wavelength of 13.5 nm ( EUV) Double exposure (double pattern lithography) of lithography and argon fluoride lithography is a candidate and has been discussed.

High-energy rays of very short wavelengths such as electron beams (EB) and X-rays. The light element such as a hydrocarbon used in a photoresist material has little absorption, and a polyhydroxystyrene-based photoresist material has been studied. In order to improve the accuracy of the line width, the exposure apparatus for mask production has started to use an exposure apparatus using an electron beam (EB) by an exposure apparatus using a laser beam. In addition, since the acceleration voltage of the electron gun of EB has been improved, it has been made finer, so it has progressed from 10 kV to 30 kV, and recently 50 kV is the mainstream, and 100 kV is also under discussion.

Here, as the acceleration voltage rises, the low sensitivity of the photoresist film becomes a problem. When the acceleration voltage is increased, the influence of the forward scattering in the photoresist film is reduced. Therefore, the contrast of the electron drawing energy is improved, and the resolution and the dimensional controllability are improved. However, since the electrons directly pass through the photoresist film, the sensitivity of the photoresist film is lowered. The mask exposure machine is exposed in a straight stroke, so that the low sensitivity of the photoresist film causes a decrease in productivity, which is not desirable. Because of the high sensitivity requirements, some people have explored chemically amplified photoresist materials.

As the miniaturization progresses, image blurring becomes a problem due to acid diffusion. In the fine pattern having a size of 45 nm or less, in order to ensure the resolution, it has been proposed that not only the improvement of the dissolution ratio proposed in the past is important, but also the control of acid diffusion is important (Non-Patent Document 1: SPIE Vol. 6520 65203L-1 (2007)). However, chemically amplified photoresist materials use acid diffusion to improve sensitivity and contrast. Therefore, if the post-exposure baking (PEB) temperature or time is shortened and the depressing acid is diffused to the limit, the sensitivity and contrast are significantly lowered.

Sensitivity and resolution and edge roughness show a triangle trade-off relationship. Here, in order to improve the resolution, it is necessary to suppress acid diffusion, but if the acid diffusion distance is shortened, the sensitivity is lowered.

It is effective to add an acid generator which generates a space barrier and suppress acid diffusion. However, an acid generator for copolymerizing a polymerized olefin with a sulfonium salt has been proposed. In JP-A-2006-045311 (Patent Document 1), a phosphonium salt or a phosphonium salt having a polymerizable olefin having a specific sulfonic acid is proposed. JP-A-2006-178317 (Patent Document 2) proposes a phosphonium salt in which a sulfonic acid is directly bonded to a main chain.

Sensitivity and edge roughness exhibit a trade-off relationship. For example, in SPIE Vol. 3331 p531 (1998) (Non-Patent Document 2), sensitivity and edge roughness are inversely proportional, and it is expected that the reduction of shot noise due to an increase in exposure amount will cause the edge of the photoresist film. The roughness is reduced. In SPIE Vol. 5374 p74 (2004) (Non-Patent Document 3), the photoresist film of the incremental quencher is effective for reducing the edge roughness, but at the same time, the sensitivity is also deteriorated, so the sensitivity of EUV and the edge roughness are in a trade-off relationship. In order to break this relationship, it is necessary to increase the quantum efficiency of acid production.

In the case of electron beam exposure, SPIE Vol. 5753 p361 (Non-Patent Document 4) proposes a mechanism for causing electrons to move toward the PAG by the excitation of the polymer and releasing the acid in the acid generation mechanism. The irradiation energy of EB and EUV is higher than the threshold 値10 eV of the ion potential energy of the base polymer, and it is presumed that the base polymer is easily released. As a material for promoting electron mobility, hydroxystyrene is exemplified.

In SPIE Vol. 5753 p1034 (2005) (Non-Patent Document 5), poly-4-hydroxystyrene has a higher acid production efficiency at the time of EB exposure than poly-4-methoxystyrene, and it is suggested that poly-4-hydroxystyrene Hydroxystyrene can move electrons to the PAG with good efficiency due to EB irradiation.

In order to improve the acid generation efficiency by electron mobility, hydroxystyrene has been proposed, and in order to reduce acid diffusion, SPIE Vol. 6519 p65191F-1 (2007) (Non-Patent Document 6) proposes that a sulfonic acid is directly bonded to a polymer backbone. A methacrylate of PAG, a material obtained by copolymerizing a methacrylate having an acid labile group. Since hydroxystyrene has a weakly acidic phenolic hydroxyl group, it has an effect of reducing swelling in an alkali developing solution, but it causes an increase in acid diffusion. On the other hand, methacrylate which is widely used as a lactone for an argon fluoride photoresist has high hydrophilicity and no alkali solubility, so it has no effect of reducing swelling, but can suppress acid. diffusion. By combining hydroxystyrene and a methacrylate having a lactone ring as an adhesion group, sensitivity can be improved, and balance between swelling reduction and acid diffusion control can be obtained, but further improvement is required. The copolymerization of hydroxyphenyl methacrylate with a methacrylate having a lactone ring and further sulfonic acid directly bonded to the PAG methacrylate of the polymer backbone can control acid diffusion while forming high with high sensitivity Resolution of the photoresist. In this case, if the sensitivity is to be further improved, it is effective to increase the ratio of hydroxyphenyl methacrylate. However, if the ratio of hydroxyphenyl methacrylate is increased, the solubility of the alkali is increased, so that the film loss of the pattern occurs and pattern collapse occurs. It is hoped that a higher sensitivity and high resolution photoresist can be developed. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Laid-Open Patent Publication No. 2006-045311 [Patent Document 2] JP-A-2006-178317 [Non-Patent Literature]

[Non-Patent Document 1] SPIE Vol. 6520 65203L-1 (2007) [Non-Patent Document 2] SPIE Vol. 3331 p531 (1998) [Non-Patent Document 3] SPIE Vol. 5374 p74 (2004) [Non-Patent Document 4] SPIE Vol. 5753 p361 (2005) [Non-Patent Document 5] SPIE Vol. 5753 p1034 (2005) [Non-Patent Document 6] SPIE Vol. 6519 p65191F-1 (2007)

(The subject to be solved by the invention)

The present invention has been made in view of the above circumstances, and an object thereof is to provide a positive photoresist material having a higher resolution than a conventional positive photoresist material and having a small edge roughness (LER, LWR) and a good pattern shape after exposure, and particularly suitable for use as a positive resist material. A positive-type photoresist material of a polymer compound of a base resin of a chemically amplified positive-type photoresist material, and a pattern forming method. (method of solving the problem)

In order to obtain a positive-type photoresist material with high sensitivity, high resolution, and small edge roughness which has been urgently required in recent years, the inventors of the present invention have tried to find that if a methacrylic acid having a third butyl group or a third pentyl group is contained, The polymer of the repeating unit of hydroxyphenyl ester is extremely effective as a positive-type photoresist material, especially as a base resin of a chemically amplified positive-type photoresist material.

Further, it has been found that, in order to suppress acid diffusion and improve dissolution contrast, a repeating unit in which a hydrogen atom of a carboxyl group is substituted with an acid labile group, and a third butyl group or a third pentyl group represented by the following formula (1) are known. The polymer obtained by copolymerization of hydroxyphenyl methacrylate is used as a positive-type photoresist material, especially as a base resin of a chemically amplified positive-type photoresist material, and the sensitivity is high and the alkali dissolution rate contrast before and after exposure is greatly improved, and the suppression is suppressed. The acid diffusion effect is high, the resolution is high, and the pattern shape and edge roughness after exposure are good, and a positive photoresist material which is particularly suitable for a micro pattern forming material for manufacturing an ultra-LSI or a photomask can be obtained, in particular, chemical amplification. Positive photoresist material. The phenol group has a sensitizing effect on EB and EUV, and has an effect of preventing swelling in an alkaline water developing solution. The sensitizer of the present invention has a phenol group and a third butyl group or a third pentyl group in the same molecule. The electron supply of the third butyl group or the third pentyl group is highly effective, and the electron density of the phenol group is increased. Thereby, the production efficiency and the sensitization effect of the secondary electrons at the time of exposure are improved, the decomposition efficiency of the acid generator is improved, and the sensitivity is improved. Since the alkali dissolution rate is low, the film loss of the pattern after alkali development can be suppressed.

The positive-type photoresist material of the present invention can particularly improve the decomposition efficiency of the acid generator, so that the sensitivity is high, the effect of suppressing acid diffusion is high, the resolution is high, the edge roughness is small, the processing suitability is excellent, and after exposure The shape of the pattern is good. Therefore, since these excellent characteristics are obtained, the practicality is extremely high, and it is very effective as a photoresist material for a super LSI and a mask pattern forming material.

That is, the present invention provides the following positive-type photoresist materials and a pattern forming method using the same. [1] A positive-type photoresist material, which comprises a weight average of a repeating unit obtained by substituting a hydrogen atom of a carboxyl group and/or a phenolic hydroxyl group with an acid labile group, and a repeating unit represented by the following formula (1) a polymer compound having a molecular weight of 1,000 to 500,000 as a base resin; (wherein R ¹ is a hydrogen atom or a methyl group, R ² is a hydrogen atom or a methyl group, and m and n are 1 or 2.) [2] A positive-type photoresist material such as [1], which is The weight average molecular weight represented by the following formula (2) wherein the repeating unit represented by the formula (a) and the repeating unit having the acid labile group represented by the following formula (b1) and/or (b2) are copolymerized is a polymer compound in the range of 1,000 to 500,000 as a base resin; (wherein R ¹ , R ² , m, and n are the same as defined above; R ³ and R ⁵ are a hydrogen atom or a methyl group; R ⁴ and R ⁸ represent an acid labile group; and R ⁶ represents a single bond or a carbon number of 1~ a linear or branched alkyl group of 6; R ⁷ represents a hydrogen atom, a fluorine atom, a trifluoromethyl group, a cyano group, or a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms; p is 1 or 2, q is an integer of 0 to 4; Y ₁ is a single bond, a linking group having an ester group, an ether group or a lactone ring having a carbon number of 1 to 12, a stretching phenyl group, or a stretching naphthyl group; ₂ is a single bond, -C(=O)-O-, or -C(=O)-NH-; 0<a<1.0, 0≦b1<1.0, 0≦b2<1.0, 0<b1+b2<1.0, 0.1≦a+b1+b2≦1.0.) [3] A positive-type photoresist material such as [2] which is substituted with a repeating unit a in the formula (2) and a hydrogen atom of a carboxyl group and/or a phenolic hydroxyl group to form an acid. a repeating unit b1 and/or b2 of an unstable group, and having a selected from the group consisting of a hydroxyl group, a carboxyl group, a lactone ring, a carbonate group, a thiocarbonate group, a carbonyl group, a cyclic acetal group, an ether group, an ester group, a sulfonate a repeating unit c (except for repeating units a, b1 and b2) of an adhesion group in a group, a cyano group, a decylamino group, -OC(=O)-G- (G is a sulfur atom or NH) Polymerized (here, 0 <c ≦ 0.9,0.2 ≦ a + b1 + b2 + c ≦ 1.0 of) the weight average molecular weight range of 1,000 to 500,000 of a polymer compound as a base resin. [4] The positive-type photoresist material of [3], which is one or more selected from the group consisting of the repeating units a, b1, b2, and c, and the phosphonium salts d1 to d3 selected from the following formula (3). The repeating unit is copolymerized (here, 0.2≦a+b1+b2+c<1.0, 0≦d1≦0.5, 0≦d2≦0.5, 0≦d3≦0.5, 0<d1+d2+d3≦0.5, 0.2<a+b1+b2+c+d1+d2+d3≦1.0) A polymer compound having a weight average molecular weight of 1,000 to 500,000 is used as a base resin. [化3] ^{(Wherein, R 20, R 24, R} 28 is a hydrogen atom or a methyl group, R ²¹ is a single bond, phenylene, -OR-, or _{-C (= O) -Y 0 -R-} ; Y 0 is An oxygen atom or NH, R is a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, an extended alkenyl group or a phenyl group, and may also contain a carbonyl group, an ester group, an ether group or a hydroxyl group; R ²² And R ²³ , R ²⁵ , R ²⁶ , R ²⁷ , R ²⁹ , R ³⁰ and R ³¹ are the same or different linear, branched or cyclic alkyl groups having 1 to 12 carbon atoms, and may also contain a carbonyl group, An ester group or an ether group, or an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 20 carbon atoms or a phenylthio group; Z ₀ represents a single bond, a methylene group, an ethyl group, a phenyl group, and a phenyl group. Fluorinated phenyl, -OR ³² -, or -C(=O)-Z ₁ -R ³² -; Z ₁ represents an oxygen atom or NH, and R ³² represents a linear or branched carbon number of 1 to 6. Or cyclic alkyl, alkenyl or phenyl, may also contain a carbonyl, ester, ether or hydroxyl group; M ^- represents a non-nucleophilic relative ion.) [5] such as [1] to [4] The positive-type photoresist material of any one of them is a chemically amplified photoresist material further containing an organic solvent and an acid generator. [6] The positive-type photoresist material such as [5] is made up of an alkaline compound and/or a surfactant which is added as an additive. [7] A pattern forming method, comprising the steps of: coating a positive photoresist material according to any one of [1] to [6] on a substrate; and performing exposure with high energy rays after heat treatment; And developing with a developing solution. [8] The pattern forming method according to [7], wherein the high energy ray to be exposed is a KrF excimer laser, an electron beam, or a soft X ray having a wavelength of 3 to 15 nm.

The use of the positive-type photoresist material of the present invention, particularly in the case of a chemically amplified positive-type photoresist material, can be applied not only to lithography such as formation of a semiconductor circuit, but also to mask circuit pattern formation, or micromechanical, A thin film magnetic head circuit is formed. (Effect of the invention)

The positive-type photoresist material of the present invention has high effect of suppressing acid diffusion, high resolution, and good pattern shape and edge roughness after exposure. Therefore, it is possible to obtain a positive-type photoresist material, particularly a chemically amplified positive-type photoresist material, which is particularly suitable for the production of a fine pattern forming material for LSI or EB drawing using a EB or a pattern forming material for EB or EUV exposure.

The invention is described in more detail below. The photoresist material of the present invention is a photoresist material characterized by using a polymer compound containing a repeating unit represented by the following formula (1) as a base resin. 【化4】 (wherein R ¹ is a hydrogen atom or a methyl group, R ² is a hydrogen atom or a methyl group, and m and n are 1 or 2.)

In this case, the base resin is particularly preferably a copolymer obtained by copolymerizing at least a repeating unit represented by the following formula (a) with a repeating unit having an acid labile group represented by the following formula (b1) and/or (b2). The polymer compound represented by the following formula (2) having a weight average molecular weight of from 1,000 to 500,000 is preferred. 【化5】 (wherein R ¹ , R ² , m and n are the same as defined above. R ³ and R ⁵ are a hydrogen atom or a methyl group, and R ⁴ and R ⁸ represent an acid labile group. R ⁶ is a single bond or a carbon number of 1~ a straight chain or branched alkyl group of 6; R ⁷ is a hydrogen atom, a fluorine atom, a trifluoromethyl group, a cyano group, or a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms; p is 1 or 2, and q is an integer of 0 to 4. Y ₁ is a single bond, has an ester group, an ether group or a lactone ring having a carbon number of 1 to 12, a phenyl group, or a naphthyl group. ₂ is a single bond, -C(=O)-O-, or -C(=O)-NH-. 0<a<1.0, 0≦b1<1.0, 0≦b2<1.0, 0<b1+b2<1.0, 0.1≦a+b1+b2≦1.0.)

The monomer Ma used to obtain the repeating unit represented by the general formula (a) is specifically exemplified below. 【化6】 (wherein R ¹ , R ² , m, and n are the same as described above.)

This monomer can be synthesized by converting one of the hydroxyl groups of the phenylated hydroquinone, resorcin, catechol, and gallicol to methacrylate. The monomer Ma for obtaining the above repeating unit a is specifically exemplified below.

【化7】 (wherein R ^{2 is the} same as above.)

Among the monomers represented above, the monomer Ma1 represented by the following formula (4) is most preferable. 【化8】 (wherein R ² is a hydrogen atom or a methyl group.)

The repeating unit a in the positive-type photoresist material of the present invention is a methacrylate having a third butyl group or a third pentyl group and a phenolic hydroxyl group in one molecule. Compared with the phenyl-free hydroxyphenyl methacrylate, the alkali dissolution rate is low, so that the film loss or pattern collapse of the pattern after development can be reduced, and the sensitization effect can be exhibited in EUV and EB exposure by increasing the introduction ratio. To improve the sensitivity.

Specific examples of the monomers Mb1 and Mb2 for obtaining the repeating units b1 and b2 having an acid labile group in the formula (2) are as follows. 【化9】 (wherein R ³ to R ⁸ , Y ₁ , Y ₂ , p, q are the same as described above.)

In this case, the linking group having the number of carbon atoms 1 to 12 of the lactone ring of Y ₁ is as follows. 【化10】

Specific examples of the monomer Mb1 used to obtain the repeating unit b1 are as follows. 【化11】 (wherein R ³ and R ^{4 are the} same as defined above.)

Specific examples of the monomer Mb2 used to obtain the repeating unit b2 are as follows. 【化12】 (wherein R ⁵ and R ^{8 are the} same as described above.)

The acid labile group (the acid labile group of R ⁴ and R ⁸ in the formula (2)) may be variously selected and may be the same or different, and particularly, the following formula (A-1) to (A-3) may be mentioned. ) the base of the replacement. 【化13】

In the formula (A-1), R ^L30 represents a carbon number of 4 to 20, preferably a tertiary alkyl group of 4 to 15, and each alkyl group is a trialkylsulfonyl group having 1 to 6 carbon atoms, and a carbon number of 4~ a pendant oxyalkyl group of 20 or a group represented by the above formula (A-3), and the tertiary alkyl group specifically includes a third butyl group, a third pentyl group, a 1,1-diethylpropyl group, and 1 -ethylcyclopentyl, 1-butylcyclopentyl, 1-ethylcyclohexyl, 1-butylcyclohexyl, 1-ethyl-2-cyclopentenyl, 1-ethyl-2-cyclohexane Examples of the alkenyl group, the 2-methyl-2-adamantyl group, and the like, and the trialkylsulfonyl group may, for example, be a trimethylsulfonyl group, a triethylsulfonyl group or a dimethyl-tert-butylfluorenyl group. Specific examples of the oxyalkyl group include a 3-oxocyclohexyl group, a 4-methyl-2-oxooxan-4-yl group, and a 5-methyl-2-oxobutylene oxide-5. - Base, etc. A1 is an integer from 0 to 6.

In the formula (A-2), R ^L31 and R ^L32 represent a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 18 carbon atoms, preferably 1 to 10, and specific examples thereof include a methyl group. Ethyl, propyl, isopropyl, n-butyl, t-butyl, tert-butyl, cyclopentyl, cyclohexyl, 2-ethylhexyl, n-octyl and the like. R ^L33 represents a monovalent hydrocarbon group having a carbon number of 1 to 18, preferably 1 to 10, and may have a hetero atom such as an oxygen atom, and examples thereof include a linear, branched or cyclic alkyl group, and a part of the hydrogen atoms. In place of a hydroxyl group, an alkoxy group, a pendant oxy group, an amine group, an alkylamine group, etc., the following substituted alkyl group etc. are mentioned specifically.

【化14】

R ^L31 and R ^L32 , R ^L31 and R ^L33 , R ^L32 and R ^L33 may also bond and form a ring together with the carbon atoms bonded thereto. When forming a ring, R ^L31 , R ^L32 , R which form a ring are formed. ^L33 represents a linear or branched alkyl group having a carbon number of 1 to 18, preferably 1 to 10, preferably a ring carbon number of 3 to 10, particularly 4 to 10.

Specific examples of the acid labile group of the above formula (A-1) include a third butoxycarbonyl group, a third butoxycarbonylmethyl group, a third pentyloxycarbonyl group, and a third pentyloxycarbonylmethyl group. 1,1-Diethylpropoxycarbonyl, 1,1-diethylpropoxycarbonylmethyl, 1-ethylcyclopentyloxycarbonyl, 1-ethylcyclopentyloxycarbonylmethyl, 1 -ethyl-2-cyclopentenyloxycarbonyl, 1-ethyl-2-cyclopentenyloxycarbonylmethyl, 1-ethoxyethoxycarbonylmethyl, 2-tetrahydropiperidyloxycarbonyl Methyl, 2-tetrahydrofuranyloxycarbonylmethyl and the like.

Further, a substituent represented by the following formula (A-1)-1 to (A-1)-10 can also be mentioned. 【化15】

Here, R ^{L37 is the} same or different from each other and is a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 20 carbon atoms, R ^L38 being a hydrogen atom, or a carbon number of 1. a linear, branched or cyclic alkyl group of ~10. Further, R ^{L39 is the} same as or different from each other and is a linear, branched or cyclic alkyl group having 2 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms. A1 is the same as above.

Among the acid labile groups represented by the above formula (A-2), those having a linear or branched shape include the following formulas (A-2)-1 to (A-2)-69. 【化16】

【化17】

【化18】

【化19】

Among the acid labile groups represented by the above formula (A-2), examples of the ring include tetrahydrofuran-2-yl, 2-methyltetrahydrofuran-2-yl, tetrahydropyran-2-yl, 2-methyl Tetrahydropyran-2-yl and the like.

Further, the base resin may be cross-linked intramolecularly or intramolecularly by using an acid labile group represented by the following formula (A-2a) or (A-2b). 【化20】

In the formula, R ^L40 and R ^L41 represent a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 8 carbon atoms. Or R ^L40 and R ^L41 may also be bonded and form a ring together with the carbon atoms bonded ^thereto . When forming a ring, R ^L40 and R ^L41 represent a linear or branched alkyl group having 1 to 8 carbon atoms. . R ^L42 represents a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, B1 and D1 are 0 or 1 to 10, preferably 0 or 1 to 5, and C1 is 1 to 7. Integer. A represents (C1+1) an aliphatic or alicyclic saturated hydrocarbon group having 1 to 50 carbon atoms, an aromatic hydrocarbon group or a heterocyclic group, and these groups may also be inserted with a hetero atom or a part of a hydrogen atom bonded to the carbon atom. It may also be substituted with a hydroxyl group, a carboxyl group, a carbonyl group or a fluorine atom. B represents -CO-O-, -NHCO-O- or -NHCONH-.

In this case, it is preferred that A is a linear, branched or cyclic alkyl group having 2 to 4 valences of 1 to 20, an alkyltriyl group, an alkyltetrayl group, and a carbon number of 6 to 30. An aryl group may have a hetero atom inserted therein, and a part of the hydrogen atom bonded to the carbon atom may be substituted with a hydroxyl group, a carboxyl group, a thiol group or a halogen atom. Further, C1 is preferably an integer of 1 to 3.

Specific examples of the crosslinked acetal group represented by the formulae (A-2a) and (A-2b) include the following formula (A-2)-70-(A-2)-77. 【化21】

Next, in the formula (A-3), R ^L34 , R ^L35 and R ^L36 are a monovalent hydrocarbon group such as a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, or a straight carbon number of 2 to 20 a chain, branched or cyclic alkenyl group, which may also contain a hetero atom such as oxygen, sulfur, nitrogen, fluorine, etc., R ^L34 and R ^L35 , R ^L34 and R ^L36 , R ^L35 and R ^L36 may also be bonded to each other and These bonded carbon atoms together form an alicyclic ring having a carbon number of 3-20.

The tertiary alkyl group represented by the formula (A-3) may, for example, be a third butyl group, a triethyl carvyl group, a 1-ethylnorbornyl group, a 1-methylcyclohexyl group, a 1-ethylcyclopentyl group, or 2 -(2-methyl)adamantyl, 2-(2-ethyl)adamantyl, third pentyl and the like.

Further, the tertiary alkyl group may specifically be represented by the following formula (A-3)-1 to (A-3)-18. 【化22】

In the formula (A-3)-1 to (A-3)-18, R ^L43 represents the same or different linear, branched or cyclic alkyl group having 1 to 8 carbon atoms, or a carbon number of 6 to 20 An aryl group such as a phenyl group. R ^L44 and R ^L46 represent a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms. R ^L45 represents 6 to 20 carbon atoms of an aryl group such as phenyl.

Further, as shown by the following formulas (A-3)-19 and (A-3)-20, a divalent or higher alkylene group, an aryl group R ^L47 may be contained, and the polymer may be intramolecularly or intermolecularly crosslinked. . 【化23】

In the formulae (A-3)-19 and (A-3)-20, R ^{L43 is the} same as ^defined above, and R ^L47 represents a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, or a phenyl group. The isoaryl group may also contain an oxygen atom or a hetero atom such as a sulfur atom or a nitrogen atom. E1 is an integer from 1 to 3.

In particular, as the acid labile group of the formula (A-3), a repeating unit of the (meth) acrylate having an exosome structure represented by the following formula (A-3)-21 can be preferably used. 【化24】 (wherein R ³ is a hydrogen atom or a methyl group. R ^Lc3 is a linear, branched or cyclic alkyl group having 1 to 8 carbon atoms or an aryl group having 6 to 20 carbon atoms which may be substituted. ^Lc4 to R ^Lc9 and R ^Lc12 and R ^Lc13 each independently represent a hydrogen atom or a monovalent hydrocarbon group having a carbon number of 1 to 15 and may contain a hetero atom, and R ^Lc10 and R ^{Lc11 may} represent a hydrogen atom or a carbon number of 1 to 15. a monovalent hydrocarbon group containing a hetero atom. R ^Lc4 and R ^Lc5 , R ^Lc6 and R ^Lc8 , R ^Lc6 and R ^Lc9 , R ^Lc7 and R ^Lc9 , R ^Lc7 and R ^Lc13 , R ^Lc8 and R ^Lc12 , R ^Lc10 and R ^Lc11 or R ^Lc11 and R ^Lc12 may also form a ring with each other, and in this case, represent a divalent hydrocarbon group having a carbon number of 1 to 15 which may also contain a hetero atom. Further, R ^Lc4 and R ^Lc13 , R ^Lc10 and R ^Lc13 or R ^Lc6 and R ^Lc8 can also be bonded to adjacent carbons to directly bond with each other and form a double bond. Also, according to this formula, it also represents a mirror image.)

Here, as a monomer for obtaining an ester body having a repeating unit having an exosome structure represented by the general formula (A-3)-21, it is shown in JP-A-2000-327633. Specifically, the following are mentioned, but it is not limited to these. 【化25】

Further, as the acid labile group of the formula (A-3), a (meth) group having a furanyl group, a tetrahydrofuranyl group or an oxalodecanediyl group represented by the following formula (A-3)-22 can be exemplified. Acrylate acid labile group. 【化26】 (In the formula, R ³ is a hydrogen atom or a methyl group. R ^Lc14 and R ^Lc15 each independently represent a linear, branched or cyclic monovalent hydrocarbon group having 1 to 10 carbon atoms. R ^Lc14 and R ^Lc15 may also be each other. The bond combines with the carbon atoms bonded ^thereto to form an aliphatic hydrocarbon ring. R ^Lc16 represents a ^divalent group selected from a furanyl group, a tetrahydrofuranyl group or an ^{oxalodecanediyl} group. R ^Lc17 represents a hydrogen atom or It may contain a linear, branched or cyclic monovalent hydrocarbon group having 1 to 10 carbon atoms of a hetero atom.)

The monomers used to obtain the repeating unit substituted with an acid labile group having a furanyl group, a tetrahydrofuranyl group or an oxalodecanediyl group are listed below. Further, Ac represents an ethyl group and Me represents a methyl group. 【化27】

【化28】

The hydrogen atom of the carboxyl group of the repeating unit b1 may also be substituted with the acid labile group represented by the following formula (A-3)-23. 【化29】 (In the formula, R ^23-1 is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group, an alkanoyl group or an alkoxycarbonyl group, an aryl group having 6 to 10 carbon atoms, a halogen atom or a cyano group. M23 is an integer from 1 to 4.)

Specific examples of the monomer having a carboxyl group substituted with an acid labile group represented by the formula (A-3)-23 are as follows. 【化30】

The hydrogen atom of the carboxyl group of the repeating unit b1 may also be substituted with the acid labile group represented by the following formula (A-3)-24. 【化31】 (wherein R ^24-1 and R ^24-2 represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group, an alkanoyl group, an alkoxycarbonyl group, a hydroxyl group, an aryl group having 6 to 10 carbon atoms, A halogen atom or a cyano group. R represents a hydrogen atom, or a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or a carbon atom having an oxygen atom or a sulfur atom. a 2~12 alkynyl group or an aryl group having 6 to 10 carbon atoms. R ^24-3 , R ^24-4 , R ^24-5 , and R ^24-6 are a hydrogen atom, or R ^24-3 and R ^{24- 4} , R ^24-4 and R ^24-5 , R ^24-5 and R ^24-6 may also be bonded to form a benzene ring. m24, n24 are integers from 1 to 4.

Specific examples of the monomer having a carboxyl group substituted with an acid labile group represented by the formula (A-3)-24 are as follows. 【化32】

【化33】

【化34】

The hydrogen atom of the carboxyl group of the repeating unit b1 may also be substituted with the acid labile group represented by the following formula (A-3)-25. 【化35】 (wherein R ^25-1 is the same or different and is a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms; and when m25 is 2 or more, R ^25-1 may be used in combination with each other. Bonding and forming a non-aromatic ring with a carbon number of 2-8, and a circle indicating a bond between carbon C _A and C _B selected from the group consisting of an exoethyl group, a propyl group, a butyl group, and a pentyl group, R ^25-2 It is an alkyl group having 1 to 4 carbon atoms, an alkoxy group, an alkyl alkoxy group, an alkoxycarbonyl group, a hydroxyl group, a nitro group, an aryl group having 6 to 10 carbon atoms, a halogen atom or a cyano group. R is as defined above. When ethyl and propyl are extended, R ^{25-1 is} not a hydrogen atom. m25 and n25 are integers of 1 to 4.

The monomer having a carboxyl group substituted with an acid labile group represented by the formula (A-3)-25 is specifically exemplified below. 【化36】

【化37】

【化38】

【化39】

【化40】

The hydrogen atom of the carboxyl group of the repeating unit b1 may also be substituted with the acid labile group represented by the following formula (A-3)-26. 【化41】 (wherein R ^26-1 and R ^26-2 are a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group, an alkanoyl group, an alkoxycarbonyl group, a hydroxyl group, a nitro group, and a carbon number of 6 to 10; An aryl group, a halogen atom, or a cyano group. R is the same as the above. m26 and n26 are integers of 1 to 4.

Specific examples of the monomer having a carboxyl group substituted with an acid labile group represented by the formula (A-3)-26 are as follows. 【化42】

【化43】

The hydrogen atom of the carboxyl group of the repeating unit b1 may also be substituted with the acid labile group represented by the following formula (A-3)-27. 【化44】 (wherein R ^27-1 and R ^27-2 are a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group, an alkanoyl group, an alkoxycarbonyl group, a hydroxyl group, an aryl group having 6 to 10 carbon atoms, A halogen atom or a cyano group. R is the same as the above. m27 and n27 are integers of 1 to 4. J is a methylene group, an ethyl group, a vinyl group, or a -CH ₂ -S- group.

The monomer having a carboxyl group substituted with an acid labile group represented by the formula (A-3)-27 is specifically exemplified below. 【化45】

【化46】

【化47】

The hydrogen atom of the carboxyl group of the repeating unit b1 may also be substituted with the acid labile group represented by the following formula (A-3)-28. 【化48】 (wherein R ^28-1 and R ^28-2 are a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group, an alkanoyl group, an alkoxycarbonyl group, a hydroxyl group, an aryl group having 6 to 10 carbon atoms, A halogen atom or a cyano group. R is the same as the above. m28 and n28 are integers of 1 to 4. K is a carbonyl group, an ether group, a thioether group, -S(=O)-, or -S(=O) ₂ -. )

Specific examples of the monomer having a carboxyl group substituted with an acid labile group represented by the formula (A-3)-28 are as follows. 【化49】

【化50】

【化51】

【化52】

【化53】

Further, in the present invention, the base resin is a repeating unit a in the formula (2), a repeating unit b1 in which a hydrogen atom of a carboxyl group is substituted with an acid labile group, and/or a phenolic hydroxyl group is substituted with an acid labile group. Repeating unit b2, and having a selected from the group consisting of a hydroxyl group, a carboxyl group, a lactone ring, a carbonate group, a thiocarbonate group, a carbonyl group, a cyclic acetal group, an ether group, an ester group, a sulfonate group, a cyano group, a decyl group And repeating unit c of -OC(=O)-G-(G is a sulfur atom or NH) is copolymerized (here, 0<c≦0.9, 0.2≦a+b1+b2+c≦1.0) A polymer compound having a weight average molecular weight of from 1,000 to 500,000 is preferred.

In order to obtain a hydroxyl group, a carboxyl group, a lactone ring, a carbonate group, a thiocarbonate group, a carbonyl group, a cyclic acetal group, an ether group, an ester group, a sulfonate group, a cyano group, a decylamino group, or an -OC ( Specific examples of the repeating unit c in which -O)-G-(G is a sulfur atom or NH) is an adhesion group, and specific examples thereof are as follows.

【化54】

【化55】

【化56】

【化57】

【化58】

【化59】

【化60】

In the case of a monomer having a hydroxyl group, the hydroxyl group may be first substituted with an acetal which is easily deprotected by an acid such as an ethoxyethoxy group, and may be deprotected by a weak acid and water after the polymerization, or may be an ethylene group first. Substituting for mercapto, trimethylethenyl, etc., and performing alkali hydrolysis after polymerization.

In the present invention, the repeating units d1, d2, and d3 having a phosphonium salt represented by the following formula (3) may be copolymerized. Japanese Laid-Open Patent Publication No. 2006-045311 proposes a phosphonium salt or a phosphonium salt having a polymerizable olefin which produces a specific sulfonic acid. Japanese Laid-Open Patent Publication No. 2006-178317 proposes a sulfonium salt in which a sulfonic acid is directly bonded to a main chain.

【化61】 (wherein R ²⁰ , R ²⁴ , and R ²⁸ are a hydrogen atom or a methyl group, and R ²¹ is a single bond, a phenyl group, a -OR-, or -C(=O)-Y ₀ -R-. Y ₀ is Oxygen atom or NH, R is a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, an alkenyl group or a phenyl group, and may also contain a carbonyl group (-CO-) or an ester group (-COO). -), an ether group (-O-) or a hydroxyl group. R ²² , R ²³ , R ²⁵ , R ²⁶ , R ²⁷ , R ²⁹ , R ³⁰ , and R ³¹ are the same or different linear chains having a carbon number of 1 to 12. a branched or cyclic alkyl group which may also contain a carbonyl group, an ester group or an ether group, or an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 20 carbon atoms or a phenylthio group. Z ₀ is a single a bond, a methylene group, an ethyl group, a phenyl group, a fluorinated phenyl group, -OR ³² -, or -C(=O)-Z ₁ -R ^{32 -.} Z ₁ is an oxygen atom or NH. R ³² is a linear, branched or cyclic alkyl, alkenyl or phenyl group having 1 to 6 carbon atoms, and may also contain a carbonyl group, an ester group, an ether group or a hydroxyl group. M ^- represents a non-nucleophilic group. Sexual relative ions.) Also, 0≦d1≦0.5, 0≦d2≦0.5, 0≦d3≦0.5, 0≦d1+d2+d3≦0.5, when blended, satisfy 0<d1+d2+d3≦0.5 and 0.2<a+b1+b2+c+d1+d2+d 3≦1.0 is preferred.

By bonding the acid generator to the polymer main chain, acid diffusion can be reduced, and the resolution can be prevented from being lowered due to blurring of acid diffusion. Further, since the acid generator is uniformly dispersed, the edge roughness (LER, LWR) can be improved.

Examples of the non-nucleophilic counter ion of M ^- include halide ions such as chloride ions and bromide ions, trifluoromethanesulfonate, 1,1,1-trifluoroethanesulfonate, and nonafluorobutane. Sulfhydryl sulfonate, sulfonate, toluenesulfonate, benzenesulfonate, 4-fluorobenzenesulfonate, 1,2,3,4,5-pentafluorobenzenesulfonate, etc., arylsulfonate, methanesulfonate, butyl Alkylsulfonate such as alkanesulfonate, bis(trifluoromethylsulfonyl) quinone imine, bis(perfluoroethylsulfonyl) quinone imine, bis(perfluorobutylsulfonyl)pyrene A methylated acid such as an amine such as hydrazine, ginseng (trifluoromethylsulfonyl) methide or ginseng (perfluoroethylsulfonyl) methide.

Further, for example, a sulfonate substituted with fluorine at the α-position represented by the following formula (K-1), a sulfonate having an α, β-position represented by the following formula (K-2), substituted with fluorine. 【化62】

In the formula (K-1), R ¹⁰² is a hydrogen atom, a linear one having a carbon number of 1 to 20, a branched or cyclic alkyl group, an alkenyl group having 2 to 20 carbon atoms, or a carbon number of 6 to 20 The aryl group may also have an ether group, an ester group, a carbonyl group, a lactone ring, or a fluorine atom. In the general formula (K-2), R ¹⁰³ is a hydrogen atom, a linear one having a carbon number of 1 to 30, a branched or cyclic alkyl group, a fluorenyl group, an alkenyl group having 2 to 20 carbon atoms, and a carbon number of 6~ The aryl or aryloxy group of 20 may also have an ether group, an ester group, a carbonyl group, or a lactone ring.

Further, when a polymer compound obtained by copolymerizing any of the repeating units of the above formula (3) is used as a base resin of a photoresist, the blending of a photoacid generator described later can be omitted.

Further, a repeating unit e derived from 茚e1, ethylene naphthalene e2, chromone e3, coumarin e4, norbornadiene e5 represented by the following formula (5) may be copolymerized. 【化63】 (wherein R ¹¹⁰ to R ¹¹⁴ are a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, a part or all of an alkyl group substituted by a halogen atom, a hydroxyl group, an alkoxy group, an alkanoyl group, an alkoxycarbonyl group, or a carbon number 6 to 10 aryl, halogen atom, or 1,1,1,3,3,3-hexafluoro-2-propanol group. X ⁰ is a methylene group, an oxygen atom, or a sulfur atom. E1≦0.5, e2 is 0≦e2≦0.5, e3 is 0≦e3≦0.5, e4 is 0≦e4≦0.5, e5 is 0≦e5≦0.5, 0≦e1+e2+e3+e4+e5≦0.5, when blended, 0<e1+e2+e3+e4+e5≦ 0.5.)

Examples of the repeating unit f which can be copolymerized other than the repeating units a, b, c, d, and e include repeating units f which are copolymerizable other than the repeating units a, b, c, d, and e, and examples thereof include styrene, A repeating unit derived from vinyl naphthalene, vinyl anthracene, vinyl anthracene, methylene indoline or the like.

In order to synthesize such a polymer compound, one of the methods is to add a radical polymerization initiator to an organic solvent to obtain a desired copolymer in a monomer which provides a repeating unit a to f. Polymer compound.

Examples of the organic solvent used in the polymerization include toluene, benzene, tetrahydrofuran, diethyl ether, dioxane, cyclohexane, cyclopentane, methyl ethyl ketone, and γ-butyrolactone. Examples of the polymerization initiator include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2,4-dimethylvaleronitrile), and 2,2-azobis ( 2-methylpropionic acid) dimethyl ester, benzammonium peroxide, laurel, etc., preferably heated to 50 to 80 ° C and polymerized. The reaction time is preferably from 2 to 100 hours, preferably from 5 to 20 hours.

When copolymerizing hydroxystyrene or hydroxyvinylnaphthalene, hydroxystyrene and hydroxyvinylnaphthalene are replaced by ethoxylated styrene and ethoxylated vinyl naphthalene. After polymerization, the above-mentioned alkali is used to hydrolyze acetamidine. A method in which an oxy group is deprotected to form polyhydroxystyrene or hydroxypolyvinylnaphthalene.

As the base in the alkaline hydrolysis, ammonia water, triethylamine or the like can be used. Further, the reaction temperature is preferably -20 to 100 ° C, preferably 0 to 60 ° C, and the reaction time is preferably 0.2 to 100 hours, preferably 0.5 to 20 hours.

Here, the ratio of the repeating units a to d satisfies 0<a<1.0, 0≦b1<1.0, 0≦b2<1.0, 0<b1+b2<1.0, 0.1≦a+b1+b2≦1.0, 0≦c≦0.9, especially 0.1. ≦a+b1+b2<1.0, 0<c≦0.9, 0≦d1≦0.5, 0≦d2≦0.5, 0≦d3≦0.5, 0≦d1+d2+d3≦0.5, preferably 0.1≦a≦0.8, 0≦b1≦0.8, 0≦b2≦0.8, 0.1≦b1+b2≦0.8, 0.1≦c≦0.8, 0≦d1≦0.4, 0≦d2≦0.4, 0≦d3≦0.4, 0≦d1+d2+d3≦0.4, more preferably 0.2≦a≦0.8 0≦b1≦0.7,0≦b2≦0.7,0.1≦b1+b2≦0.7,0.1≦c≦0.8,0≦d1≦0.3,0≦d2≦0.3,0≦d3≦0.3,0≦d1+d2+d3≦0.3, again More preferably, 0.2≦a≦0.7, 0≦b1≦0.6, 0≦b2≦0.6, 0.1≦b1+b2≦0.6, 0.2≦c≦0.7, 0≦d1≦0.2, 0≦d2≦0.2, 0≦d3≦0.2 , 0≦d1+d2+d3≦0.25. Further, the ratio of the repeating units e and f satisfies 0≦e1≦0.5, 0≦e2≦0.5, 0≦e3≦0.5, 0≦e4≦0.5, 0≦e5≦0.5, preferably 0≦e1≦0.4, 0≦e2≦0.4, 0≦e3≦0.4, 0≦e4≦0.4, 0≦e5≦0.4, more preferably 0≦e1≦0.3, 0≦e2≦0.3, 0≦e3≦0.3, 0≦e4≦0.3 0 ≦ e5 ≦ 0.3, 0 ≦ f ≦ 0.5, preferably 0 ≦ f ≦ 0.4, and more preferably 0 ≦ f ≦ 0.3. Further, a+b1+b2+c+d1+d2+d3+e1+e2+e3+e4+e5+f=1 is preferable.

The polymer compound used in the positive-type photoresist material of the present invention has a weight average molecular weight of 1,000 to 500,000, preferably 2,000 to 30,000. If the weight average molecular weight is too small, the heat resistance of the photoresist material is not good. If it is too large, the alkali solubility is low, and the tailing phenomenon is likely to occur after the pattern is formed. Further, the weight average molecular weight (Mw) was measured by polystyrene conversion using gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent.

Further, in the polymer compound used in the positive-type photoresist material of the present invention, when the molecular weight distribution (Mw/Mn) of the multi-component copolymer is wide, a polymer having a low molecular weight or a high molecular weight is present on the pattern after exposure. Foreign matter can be observed, or the shape of the pattern deteriorates. Therefore, as the pattern rule is refined, the influence of such molecular weight and molecular weight distribution is easily increased. Therefore, in order to obtain a photoresist material suitable for a fine pattern size, the molecular weight distribution of the multicomponent copolymer used is 1.0 to 2.0, especially It is preferably a narrow dispersion of 1.0 to 1.5. It is also possible to mix two or more kinds of polymers having different composition ratios or molecular weight distributions or molecular weights, or polymers which are not copolymerized with the repeating unit a represented by the general formula (2).

The polymer compound used in the present invention is suitable as a base resin of a positive-type photoresist material, and such a polymer compound is used as a base resin, and an organic solvent, an acid generator, a dissolution inhibitor, and a base are appropriately combined therein depending on the purpose. a compound, a surfactant, a crosslinking agent, or the like, and blended to form a positive-type photoresist material. In the exposed portion, the polymer compound accelerates the dissolution rate of the developer by a catalyst reaction, and thus can become a pole High-sensitivity positive-type photoresist material, the photoresist film has high dissolution contrast and resolution, excellent exposure latitude, good process adaptability, good pattern shape after exposure, and excellent etching resistance, and at the same time Since acid diffusion is suppressed, the difference in size is small, so that it is highly practical, and it is very effective as a photoresist material for super LSI. In particular, if an acid-amplifying agent is contained and a chemically amplified positive-type photoresist material which is reacted by an acid catalyst is used, it can be made into a higher sensitivity, and at the same time, various characteristics are more excellent, and it is extremely useful.

Further, by blending the dissolution control agent with the positive-type photoresist material, the difference in the dissolution rate between the exposed portion and the unexposed portion can be further increased, and the resolution can be further improved.

Further, by adding a basic compound, for example, the diffusion rate of the acid in the photoresist film can be suppressed, the resolution can be further improved, and the coating property of the photoresist can be further improved or controlled by adding a surfactant.

In the positive-type photoresist material of the present invention, in order to function as a chemically amplified positive-type photoresist material used in the pattern forming method of the present invention, an acid generator may be contained, and for example, an active light or radiation may be contained to generate an acid. Compound (photoacid generator). The component of the photoacid generator may be any compound which can generate an acid by irradiation with high energy rays. Desirable photoacid generators include cerium salt, cerium salt, sulfonyldiazomethane, N-sulfonyloxy quinone imine, hydrazine-O-sulfonate type acid generator, and the like. Although the details are as follows, these may be used alone or in combination of two or more. Specific examples of the acid generator are described in paragraphs [0122] to [0142] of JP-A-2008-111103.

The photoresist of the present invention may further contain at least one of an organic solvent, a basic compound, a dissolution controlling agent, a surfactant, and an acetylene alcohol. Specific examples of the organic solvent are described in paragraphs [0144] to [0145] of JP-A-2008-111103, basic compounds are described in paragraphs [0146] to [0164], and surfactants are described in paragraph [0165]. [0166] The dissolution control agent is described in paragraphs [0155] to [0178] of JP-A-2008-122932, and acetylene alcohols are described in paragraphs [0179] to [0182]. A polymer type quencher described in JP-A-2008-239918 may also be added. By aligning the surface of the photoresist after coating, the rectangularity of the patterned photoresist can be improved. The polymer type quenching agent also has an effect of preventing film loss of the pattern when the protective film is used for the photoresist or rounding of the top of the pattern.

Further, the blending amount of the acid generator is preferably 0.01 to 100 parts by mass, particularly preferably 0.1 to 80 parts by mass, based on 100 parts by mass of the base resin, and the blending amount of the organic solvent is 50 parts by mass based on 100 parts by mass of the base resin. It is preferably -10,000 parts by mass, especially 100 to 5,000 parts by mass. Further, the amount of the dissolution controlling agent is 0 to 50 parts by mass, particularly 0 to 40 parts by mass, and the basic compound is 0 to 100 parts by mass, particularly 0.001 to 50 parts by mass, and the surfactant is 0, based on 100 parts by mass of the base resin. The blending amount of ~10 parts by mass, particularly 0.0001 to 5 parts by mass, is preferred.

The positive-type photoresist material of the present invention, for example, a chemically amplified positive-type photoresist material containing an organic solvent, the above polymer compound, an acid generator, and a basic compound is used in the production of various integrated circuits, and is not particularly limited and can be used. Known lithography technology.

For example, the positive resist material of the present invention is applied to a substrate for integrated circuit fabrication (Si, SiO ₂ , SiN by a suitable coating method such as spin coating, roll coating, flow coating, dip coating, spray coating, blade coating, or the like). On a substrate for manufacturing a mask circuit (Cr, CrO, CrON, MoSi, etc.), a substrate for manufacturing a mask circuit (such as SiON, TiN, WSi, BPSG, SOG, or an organic antireflection film), the film thickness is 0.1 to 2.0 μm. It is pre-baked on a hot plate at 60 to 150 ° C for 10 seconds to 30 minutes, preferably at 80 to 120 ° C for 30 seconds to 20 minutes. A protective film can also be applied to the photoresist film. The protective film is preferably of a type which is soluble in an alkali developing solution, and simultaneously forms a resist pattern and peels off the protective film during development. The protective film has the following functions: reducing the action of the fugitive gas from the photoresist film, and acting as a filter for preventing the extra-frequency (OOB) light having a wavelength of 140 to 300 nm other than 13.5 nm generated by the EUV laser, and preventing the environment The shape that affects the photoresist becomes a function of top stretching or film loss. Next, the target pattern is passed through a predetermined mask using a light source selected from the group consisting of ultraviolet rays, far ultraviolet rays, electron beams, X-rays, excimer lasers, gamma rays, synchrotron radiation, and vacuum ultraviolet rays (soft X-rays). Or direct exposure. The exposure amount is preferably such that the exposure is about 1 to 200 mJ/cm ² , especially about 10 to 100 mJ/cm ² , or about 0.1 to 100 μC/cm ² , particularly preferably about 0.5 to 50 μC/cm ² . Next, it is carried out on a hot plate at 60 to 150 ° C for 10 seconds to 30 minutes, preferably at 80 to 120 ° C for 30 seconds to 20 minutes after exposure and baking (PEB).

Then, 0.1 to 10% by mass, preferably 2 to 5% by mass, of tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide (TPAH), and tetrabutylate are used. a developing solution of an aqueous alkali solution such as ammonium hydroxide (TBAH) for 3 seconds to 3 minutes, preferably 5 seconds to 2 minutes, by dip method, puddle method, spray method, etc. The development of the method causes the irradiated portion to be dissolved in the developing solution, and the unexposed portion is not dissolved, and a desired positive pattern is formed on the substrate. Further, the photoresist material of the present invention is particularly preferably used for fine patterning by electron beams, vacuum ultraviolet rays (soft X-rays), X-rays, gamma rays, and synchrotron radiation in high-energy rays. Compared with the widely used TMAH aqueous solution, TEAH, TPAH, and TBAH having an elongated alkyl chain have an effect of reducing swelling during development and preventing pattern collapse. Japanese Patent No. 3,429,592 discloses that a repeating unit having an alicyclic structure such as adamantyl methacrylate and a repeating unit having an acid labile group such as a third butyl methacrylate are copolymerized to eliminate hydrophilicity. For the development of a high water-repellent polymer, an example of an aqueous solution of TBAH was used. The tetramethylammonium hydroxide (TMAH) developer is most widely used as a 2.38 mass% aqueous solution. It is equivalent to 0.26N, and the TEAH, TPAH, and TBAH aqueous solutions are preferably the same degree of regulation. The mass of TEAH, TPAH, and TBAH of 0.26 N was 3.84% by mass, 5.31% by mass, and 6.78% by mass. In the pattern of 32 nm or less in which EB and EUV are resolved, there is a phenomenon in which the line is twisted, the lines are entangled, and the entangled line collapses. The reason for this is considered to be that the lines which are swollen in the developing solution and which are swollen are entangled with each other. The swelled thread is soft like a sponge because it contains a developing solution, so it is liable to collapse due to the stress of the rinsing. For the reason of this, the alkyl chain-extended developer has an effect of preventing swelling and preventing the pattern from collapsing.

A negative pattern can also be obtained by developing with an organic solvent. The developer may be selected from the group consisting of 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, methyl Cyclohexanone, acetophenone, methyl acetophenone, propyl acetate, butyl acetate, isobutyl acetate, amyl acetate, butenyl acetate, isoamyl acetate, phenyl acetate, propyl formate, formic acid Butyl ester, isobutyl formate, amyl formate, isoamyl formate, methyl valerate, methyl pentenoate, methyl crotonate, ethyl crotonate, methyl propionate, ethyl propionate, 3- Ethyl ethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, amyl lactate, isoamyl lactate, methyl 2-hydroxyisobutyrate, 2-hydroxyl Ethyl isobutyrate, methyl benzoate, ethyl benzoate, benzyl acetate, methyl phenylacetate, benzyl formate, phenylethyl formate, methyl 3-phenylpropionate, benzyl propionate, One or more of ethyl phenylacetate and 2-phenylethyl acetate.

Rinse at the end of development. The eluent is preferably a solvent which is miscible with the developer and does not dissolve the photoresist film. As such a solvent, an alcohol having 3 to 10 carbon atoms, an ether compound having 8 to 12 carbon atoms, an alkane having 6 to 12 carbon atoms, an alkene or an alkyne aromatic solvent is preferably used.

Specifically, examples of the alkane having 6 to 12 carbon atoms include hexane, heptane, octane, decane, decane, undecane, dodecane, methylcyclopentane, dimethylcyclopentane, and a ring. Hexane, methylcyclohexane, dimethylcyclohexane, cycloheptane, cyclooctane, cyclodecane, and the like. Examples of the olefins having 6 to 12 carbons include hexene, heptene, octene, cyclohexene, methylcyclohexene, dimethylcyclohexene, cycloheptene, cyclooctene, etc., carbon number 6 to 12 Examples of the deficiency include hexene, heptene, and octene. Examples of the alcohol having 3 to 10 carbon atoms include n-propanol, isopropanol, 1-butanol, 2-butanol, isobutanol, and third butanol. , 1-pentanol, 2-pentanol, 3-pentanol, third pentanol, neopentyl alcohol, 2-methyl-1-butanol, 3-methyl-1-butanol, 3-methyl- 3-pentanol, cyclopentanol, 1-hexanol, 2-hexanol, 3-hexanol, 2,3-dimethyl-2-butanol, 3,3-dimethyl-1-butanol, 3,3-Dimethyl-2-butanol, 2-ethyl-1-butanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-methyl-3- Pentanol, 3-methyl-1-pentanol, 3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl-1-pentanol, 4-methyl-2- Pentanol, 4-methyl-3-pentanol, cyclohexanol, 1-octanol, and the like. Examples of the ether compound having 8 to 12 carbon atoms are selected from the group consisting of di-n-butyl ether, di-isobutyl ether, di-second dibutyl ether, di-n-pentyl ether, diisoamyl ether, di-second pentyl ether, and di-third pentane. One or more solvents selected from the group consisting of ether and di-n-hexyl ether. In addition to the above solvent, an aromatic solvent such as toluene, xylene, ethylbenzene, cumene, tert-butylbenzene or mesitylene may also be used. [Examples]

The present invention will be specifically described below by way of Synthesis Examples, Comparative Synthesis Examples, Examples and Comparative Examples, but the present invention is not limited to the following examples.

Further, the weight average molecular weight (Mw) was measured by polystyrene conversion using gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent. Further, the monomers 1, 2, the adhesive monomer 1 and the PAG monomers 1 to 5 used in the following synthesis examples are as follows.

【化64】 Monomer 1: Methacrylic acid (4-hydroxy-3-tributyl ester) Monomer 2: Methacrylic acid (3-hydroxy-3-tripentyl ester)

【化65】 Adhesive monomer 1: methacrylic acid (2-o-oxy-1,3-benzoxyl mercaptan-5-ester)

【化66】 PAG monomer 1: 1,1,3,3,3-pentafluoro-2-methylpropenyloxypropane-1-sulfonic acid triphenylsulfonium PAG monomer 2:1,1,3,3,3- Pentafluoro-2-(methacrylooxime)propane-1-sulfonic acid 5-phenyldibenzothiophene PAG monomer 3:1,1,3,3,3-pentafluoro-2-(3- Methyl propylene oxime-adamantane-1-carbonyloxy)-propane-1-sulfonic acid triphenyl sulfonium PAG monomer 4:1,1,3,3,3-pentafluoro-2-(3-A Propylene oxime-adamantane-1-carbonyloxy)-propane-1-sulfonic acid 5-phenyldibenzothiophene PAG monomer 5:1,1,3,3,3-pentafluoro-2- (3-Methylacryloyloxy-adamantane-1-carbonyloxy)-propane-1-sulfonic acid 10-phenylmorphoquinone

[Synthesis Example 1] To a 2 L flask, 8.2 g of ethylcyclopentanyl methacrylate, 7.0 g of a monomer 1, 7.1 g of 4-hydroxyphenyl methacrylate, and 40 g of tetrahydrofuran as a solvent were added. The reaction vessel was cooled to -70 ° C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After warming to room temperature, 1.2 g of AIBN (azobisisobutyronitrile) as a polymerization initiator was added, and the mixture was heated to 60 ° C, and then allowed to react for 15 hours. This reaction solution was precipitated in a 1 L solution of isopropyl alcohol, and the obtained white solid was filtered, and then dried under reduced pressure at 60 ° C to obtain a white polymer. The obtained polymer was subjected to ¹³ C, ¹ H-NMR, and GPC measurement to obtain the following analysis results. <Copolymerization composition ratio> (Mohr ratio) Ethyl cyclopentyl methacrylate: Monomer 1: 4-hydroxyphenyl methacrylate = 0.30: 0.30: 0.40 Weight average molecular weight (Mw) = 9,100 Molecular weight distribution ( Mw/Mn) = 1.94 The polymer compound was (polymer 1). 【化67】

[Synthesis Example 2] To a 2 L flask was added 3-ethyl-3-exotetracyclomethacrylate [4.4.0.1 ^2,5 .1 ^7,10 ] dodecyl ester 6.3 g, 7.0 g of monomer 1, oxime 1.7 g, 6.0 g of 4-acetoxystyrene, and 40 g of tetrahydrofuran as a solvent. The reaction vessel was cooled to -70 ° C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After warming to room temperature, 1.2 g of AIBN (azobisisobutyronitrile) as a polymerization initiator was added, and the mixture was heated to 60 ° C, and then allowed to react for 15 hours. The reaction solution was precipitated in a 1 L solution of isopropanol, and the obtained white solid was redissolved in a mixed solvent of 100 mL of methanol and 200 mL of tetrahydrofuran, and 10 g of triethylamine and 10 g of water were added thereto, and the ethyl sulfonate was carried out at 70 ° C for 5 hours. The deprotection reaction was neutralized with acetic acid. After concentrating the reaction solution, it was dissolved in 100 mL of acetone, and the same precipitation as above was carried out, filtered, and dried at 60 ° C to obtain a white polymer. The obtained polymer was subjected to ¹³ C, ¹ H-NMR, and GPC measurement, and as a result, the following analysis results were obtained. <copolymerization composition ratio> (mole ratio) 3-ethyl-3-exo-tetracyclic methacrylate [4.4.0.1 ^2,5 .1 ^7,10 ] dodecyl ester: monomer 1: oxime: 4-hydroxyl Styrene = 0.23: 0.30: 0.10: 0.37 Weight average molecular weight (Mw) = 8,200 Molecular weight distribution (Mw / Mn) = 1.69 Let the polymer compound be (Polymer 2). 【化68】

[Synthesis Example 3] 6.2 g of methylcyclohexyl methacrylate, 7.0 g of a monomer 1, 1.7 g of vinyl naphthalene, 6.0 g of 4-ethenyloxystyrene, and tetrahydrofuran as a solvent were added to a 2 L flask. 40g. The reaction vessel was cooled to -70 ° C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After warming to room temperature, 1.2 g of AIBN (azobisisobutyronitrile) as a polymerization initiator was added, and the mixture was heated to 60 ° C, and then allowed to react for 15 hours. The reaction solution was precipitated in a 1 L solution of isopropanol, and the obtained white solid was redissolved in a mixed solvent of 100 mL of methanol and 200 mL of tetrahydrofuran, and 10 g of triethylamine and 10 g of water were added thereto, and 5-ethyl group was carried out at 70 ° C for 5 hours. The deprotection reaction was neutralized using acetic acid. After concentrating the reaction solution, it was dissolved in 100 mL of acetone, and precipitated, filtered, and dried at 60 ° C to obtain a white polymer. ¹³ C, ¹ H-NMR, and GPC measurement of the obtained polymer were carried out, and the following analysis results were obtained. <Copolymerization composition ratio> (Mohr ratio) Methylcyclohexyl methacrylate: Monomer 1: Ethylene naphthalene: 4-hydroxystyrene = 0.25: 0.30: 0.10: 0.35 Weight average molecular weight (Mw) = 7,100 Molecular weight The distribution (Mw/Mn) = 1.59 makes this polymer compound (Polymer 3). 【化69】

[Synthesis Example 4] To a 2 L flask was added 3-ethyl-3-exotetracyclomethacrylate [4.4.0.1 ^2,5 .1 ^7,10 ] dodecyl ester 8.2 g, 7.0 g of monomer 1, 7.1 g of the adhesive monomer 1, 5.6 g of the PAG monomer 1, and 40 g of tetrahydrofuran as a solvent. The reaction vessel was cooled to -70 ° C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After warming to room temperature, 1.2 g of AIBN (azobisisobutyronitrile) as a polymerization initiator was added, and the mixture was heated to 60 ° C, and then allowed to react for 15 hours. This reaction solution was precipitated in a 1 L solution of isopropyl alcohol, and the obtained white solid was filtered, and then dried under reduced pressure at 60 ° C to obtain a white polymer. ¹³ C, ¹ H-NMR, and GPC measurement of the obtained polymer were carried out, and the following analysis results were obtained. <copolymerization composition ratio> (mole ratio) 3-ethyl-3-exo-tetracyclic methacrylate [4.4.0.1 ^2,5 .1 ^7,10 ] dodecyl ester: monomer 1: adhesive monomer 1: PAG monomer 1 = 0.30: 0.30: 0.30: 0.10 Weight average molecular weight (Mw) = 7,100 Molecular weight distribution (Mw / Mn) = 1.75 The polymer compound was (polymer 4). 【化70】

[Synthesis Example 5] To a 2 L flask was added 3-ethyl-3-exotetracyclomethacrylate [4.4.0.1 ^2,5 .1 ^7,10 ] dodecyl ester 5.5 g, third pentyloxystyrene 2.9 g, 7.4 g of monomer 2, 3-octyl oxy-2,7-dioxatricyclo[4.2.1.0 ^4,8 ]non-9-ester 4.4 g, 5.6 g of PAG monomer 2. 40 g of tetrahydrofuran as a solvent. The reaction vessel was cooled to -70 ° C under a nitrogen atmosphere, and degassed under reduced pressure three times and nitrogen was blown. After warming to room temperature, 1.2 g of AIBN (azobisisobutyronitrile) as a polymerization initiator was added, and the mixture was heated to 60 ° C, and then allowed to react for 15 hours. This reaction solution was precipitated in a 1 L solution of isopropyl alcohol, and the obtained white solid was filtered, and then dried under reduced pressure at 60 ° C to obtain a white polymer. ¹³ C, ¹ H-NMR, and GPC measurement of the obtained polymer were carried out, and the following analysis results were obtained. <copolymerization composition ratio> (mole ratio) 3-ethyl-3-exo-tetracyclic methacrylate [4.4.0.1 ^2,5 .1 ^7,10 ] dodecyl ester: third pentoxy styrene: single Body 2: 3-Acetyl-2,7-dioxatricyclomethacrylate [4.2.1.0 ^4,8 ]壬-9-ester: PAG monomer 2=0.20:0.15:0.30:0.25:0.10 Weight Average molecular weight (Mw) = 8,500 Molecular weight distribution (Mw / Mn) = 1.55 Let this polymer compound be (Polymer 5). 【化71】

[Synthesis Example 6] 5.2 g of 1-(adamantan-1-yl)-1-methylethyl methacrylate, 2.9 g of a third pentyloxystyrene, and 7.0 g of a monomer 1 were placed in a 2 L flask. ⁴ -Phenyloxy-2,7-dioxatricyclo[4.2.1.0 ^4,8 ]dec-9-ester 4.5 g, 11.0 g of PAG monomer 4, 40 g of tetrahydrofuran as a solvent. The reaction vessel was cooled to -70 ° C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After warming to room temperature, 1.2 g of AIBN (azobisisobutyronitrile) as a polymerization initiator was added, and the mixture was heated to 60 ° C, and then allowed to react for 15 hours. This reaction solution was precipitated in a 1 L solution of isopropyl alcohol, and the obtained white solid was filtered, and then dried under reduced pressure at 60 ° C to obtain a white polymer. ¹³ C, ¹ H-NMR, and GPC measurement of the obtained polymer were carried out, and the following analysis results were obtained. <copolymerization composition ratio> (mole ratio) 1-(adamantan-1-yl)-1-methylethyl methacrylate: third pentyloxystyrene: monomer 1: methacrylic acid 3-side Oxy-2,7-dioxatricyclo[4.2.1.0 ^4,8 ]dec-9-ester: PAG monomer 4=0.20:0.15:0.30:0.20:0.15 Weight average molecular weight (Mw)=10,200 Molecular weight distribution (Mw/Mn) = 1.88 Let the polymer compound be (polymer 6). 【化72】

[Synthesis Example 7] 5.2 g of 1-(cyclopropen-1-yl)-1-methylethyl methacrylate, 2.9 g of a third pentyloxystyrene, and 7.4 g of a monomer 2 were placed in a 2 L flask. 2.6 g of 2-oxoxyoxacyclopentane-3-ester methacrylate, 15.0 g of PAG monomer 5, and 40 g of tetrahydrofuran as a solvent. The reaction vessel was cooled to -70 ° C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After warming to room temperature, 1.2 g of AIBN (azobisisobutyronitrile) as a polymerization initiator was added, and the mixture was heated to 60 ° C, and then allowed to react for 15 hours. This reaction solution was precipitated in a 1 L solution of isopropyl alcohol, and the obtained white solid was filtered, and then dried under reduced pressure at 60 ° C to obtain a white polymer. ¹³ C, ¹ H-NMR, and GPC measurement of the obtained polymer were carried out, and the following analysis results were obtained. <copolymerization composition ratio> (mole ratio) 1-(cyclopropen-1-yl)-1-methylethyl methacrylate: third pentyloxystyrene: monomer 2: methacrylic acid-2- Sideoxyoxolane-3-ester: PAG monomer 5=0.20:0.15:0.30:0.15:0.20 Weight average molecular weight (Mw)=10,100 Molecular weight distribution (Mw/Mn)=1.81 Let this polymer compound be (Polymer 7). 【化73】

[Synthesis Example 8] 8.2 g of isopropylcyclopentan methacrylate, 7.0 g of monomer 1, and 3-sided oxy-2,7-dioxatricyclo[4-cyclobutylene] were added to a 2 L flask. .1.0 ^4,8 ] -9-ester 5.6 g, 11.0 g of PAG monomer 3, 40 g of tetrahydrofuran as a solvent. The reaction vessel was cooled to -70 ° C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After warming to room temperature, 1.2 g of AIBN (azobisisobutyronitrile) as a polymerization initiator was added, and the mixture was heated to 60 ° C, and then allowed to react for 15 hours. This reaction solution was precipitated in a 1 L solution of isopropyl alcohol, and the obtained white solid was filtered, and then dried under reduced pressure at 60 ° C to obtain a white polymer. ¹³ C, ¹ H-NMR, and GPC measurement of the obtained polymer were carried out, and the following analysis results were obtained. <copolymerization composition ratio> (mole ratio) isopropylcyclopentanyl methacrylate: monomer 1: 3-ethyloxy-2,7-dioxatricyclomethacrylate [4.2.1.0 ^4,8 ]壬-9-ester: PAG monomer 3=0.30:0.30:0.25:0.15 Weight average molecular weight (Mw)=7,700 Molecular weight distribution (Mw/Mn)=1.67 The polymer compound was (polymer 8). 【化74】

[Comparative Synthesis Example 1] The following polymers were synthesized in the same manner as in the above Synthesis Example. <copolymerization composition ratio> (mole ratio) 3-ethyl-3-exotetracyclyl methacrylate [4.4.0.1 ^2,5 .1 ^7,10 ] dodecyl ester: 4-hydroxyphenyl methacrylate = 0.30: 0.70 Weight average molecular weight (Mw) = 9,900 Molecular weight distribution (Mw/Mn) = 1.99 Let this polymer compound be (Comparative Polymer 1). 【化75】

[Comparative Synthesis Example 2] The following polymer was synthesized in the same manner as in the above Synthesis Example. <copolymerization composition ratio> (mole ratio) 3-ethyl-3-exo-tetracyclic methacrylate [4.4.0.1 ^2,5 .1 ^7,10 ] dodecyl ester: 4-methoxy-3-hydroxyl group Styrene = 0.30: 0.70 Weight average molecular weight (Mw) = 9,700 Molecular weight distribution (Mw / Mn) = 1.79 Let this polymer compound be (Comparative Polymer 2). 【化76】

[Comparative Synthesis Example 3] The following polymer was synthesized in the same manner as in the above Synthesis Example. <copolymerization composition ratio> (mole ratio) 3-ethyl-3-exo-tetracyclic methacrylate [4.4.0.1 ^2,5 .1 ^7,10 ] dodecyl ester: 4-hydroxy-3,5-di Methylbenzylmethacrylamide = 0.30: 0.70 Weight average molecular weight (Mw) = 9,300 Molecular weight distribution (Mw / Mn) = 1.72 Let this polymer compound be (Comparative Polymer 3). 【化77】

[Comparative Synthesis Example 4] The following polymer was synthesized in the same manner as in the above Synthesis Example. <copolymerization composition ratio> (mole ratio) 3-ethyl-3-exo-tetracyclic methacrylate [4.4.0.1 ^2,5 .1 ^7,10 ] dodecyl ester: 4-hydroxyphenyl methacrylate: 3-Ethyloxy-2,7-dioxatricyclomethacrylate [4.2.1.0 ^4,8 ]壬-9-ester: PAG monomer 1=0.30:0.20:0.40:0.10 Weight average molecular weight (Mw) = 7,300 Molecular weight distribution (Mw/Mn) = 1.88 Let this polymer compound be (Comparative Polymer 4). 【化78】

[Examples and Comparative Examples] Using the polymer compound synthesized above, the composition shown in Table 1 was dissolved in a solvent of FC-4430 in which a surfactant of 3 μm (manufactured by Sumitomo 3M) as a surfactant was dissolved. The solution was filtered through a filter having a size of 0.2 μm to prepare a positive photoresist material. The compositions in Table 1 are as follows. Polymers 1 to 8: Polymer compounds obtained in the above Synthesis Examples 1 to 8 Comparative Polymers 1 to 4: Polymer Compounds obtained by the above Comparative Synthesis Examples 1 to 4: PGMEA (propylene glycol monomethyl ether acetate) PGME (propylene glycol monomethyl ether) CyH (cyclohexanone) acid generator: PAG1 (refer to the following structural formula) Basic compound: Amine1, 2 (refer to the following structural formula)

<Electron beam drawing evaluation> A positive-type photoresist material obtained on a Si substrate having a diameter of 6 吋φ of hexamethyldioxane (HMDS) subjected to steam pretreatment was used, and a Clean track Mark 5 (Tokyo Power) was used. The Kodak Co., Ltd. was spin-coated and prebaked on a hot plate at 110 ° C for 60 seconds to prepare a 100 nm photoresist film. The HL-800D manufactured by Hitachi, Ltd. was used, and the vacuum chamber was drawn at a HV voltage of 50 kV. Immediately after drawing, Clean Track Mark 5 (manufactured by Tokyo Weishi Kecco Co., Ltd.) was used, and 60 seconds of post-exposure baking (PEB) was carried out on a hot plate at the temperature shown in Table 1, and carried out for 30 seconds with a 2.38 mass% TMAH aqueous solution. Dip development to obtain a positive pattern. The obtained photoresist pattern was evaluated in the following manner. The line and pitch of 100 nm were defined as the resolution of the smallest of the 1:1 resolution, and the edge roughness (LWR) of 100 nm LS was measured by SEM. The results of the photoresist composition and the sensitivity and resolution of the EB exposure are shown in Table 1.

[Table 1] <TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> </td><td> Polymer (parts by mass) </td> <td> Acid generator (parts by mass) </td><td> Basic compound (parts by mass) </td><td> Organic solvent (parts by mass) </td><td> PEB temperature (°C) < /td><td> Sensitivity (μC/cm²) </td><td> Resolution (nm) </td><td> LWR (nm) </td></tr> <tr><td> Example 1-1 </td><td> Polymer 1 (100) </td><td> PAG 1 (30) </td><td> Amine 1 (1.8) </ Td><td> PGMEA(1,500) CyH(200) </td><td> 90 </td><td> 28.6 </td><td> 70 </td><td> 6.1 </td>< /tr><tr><td> Example 1-2 </td><td> Polymer 2 (1003 </td><td> PAG 1 (30) </td><td> Amine 1 (1.8) </td><td> PGMEA(1,500) CyH(200) </td><td> 95 </td><td> 28.4 </td><td> 70 </td><td> 6.0 </td ></tr><tr><td> Example 1-3 </td><td> Polymer 3 (100) </td><td> PAG 1 (30) </td><td> Amine 1 (1.8) </td><td> PGMEA(1,500) CyH(200) </td><td> 95 </td><td> 29.3 </td><td> 70 </td><td> 5.7 </td></tr><tr><td> Example 1-4 </td><td> Polymer 4 (100) </td><t d> - </td><td> Amine 1 (1.2) </td><td> PGMEA(500) CyH(1,450) PGME(50) </td><td> 95 </td><td> 27.3 </td><td> 65 </td><td> 4.1 </td></tr><tr><td> Example 1-5 </td><td> Polymer 5 (100) </ Td><td> - </td><td> Amine 1 (1.2) </td><td> PGMEA(500) CyH(1,450) PGME(50) </td><td> 95 </td>< Td> 28.1 </td><td> 65 </td><td> 4.0 </td></tr><tr><td> Example 1-6 </td><td> Polymer 6 (100 </td><td> - </td><td> Amine 1 (1.2) </td><td> PGMEA(500) CyH(1,450) PGME(50) </td><td> 90 </ Td><td> 26.3 </td><td> 65 </td><td> 3.8 </td></tr><tr><td> Example 1-7 </td><td> Polymer 7 (100) </td><td> - </td><td> Amine 2 (0.8) </td><td> PGMEA(500) CyH(1,450) PGME(50) </td><td> 90 </td><td> 27.2 </td><td> 65 </td><td> 3.6 </td></tr><tr><td> Example 1-8 </td><td > Polymer 8 (100) </td><td> - </td><td> Amine 1 (1.2) </td><td> PGMEA(500) CyH(1,450) PGME(50) </td> <td> 90 </td><td> 28.2 </td><td> 65 </td><td> 3.7 </td></tr><tr><td> Comparative Example 1-1 </td ><td> Comparative Polymer 1 (100) </td><td> PAG 1 (30) </td><td> Amine 1 (1.8) </td><td> PGMEA(1,500) CyH(200) </td><td> 90 </td><td> 29.5 </ Td><td> 90 </td><td> 7.9 </td></tr><tr><td> Comparative Example 1-2 </td><td> Comparative Polymer 2 (100) </td ><td> PAG 1 (30) </td><td> Amine 1 (1.8) </td><td> PGMEA(1,500) CyH(200) </td><td> 90 </td><td > 33.5 </td><td> 90 </td><td> 7.8 </td></tr><tr><td> Comparative Example 1-3 </td><td> Comparative Polymer 3 (100 ) </td><td> PAG 1 (30) </td><td> Amine 1 (1.8) </td><td> PGMEA(1,500) CyH(200) </td><td> 95 </ Td><td> 39.5 </td><td> 90 </td><td> 7.6 </td></tr><tr><td> Comparative Example 1-5 </td><td> Comparative Polymerization 4 (100) </td><td> - </td><td> Amine 1 (1.2) </td><td> PGMEA(500) CyH(1,450) PGME(50) </td><td > 90 </td><td> 36.0 </td><td> 70 </td><td> 6.4 </td></tr></TBODY></TABLE>

<EUV Exposure Evaluation> A solution obtained by dissolving the polymer compound synthesized above in the composition shown in Table 2 was filtered through a filter having a size of 0.2 μm to prepare a positive resist material. The obtained positive photoresist material was spin-coated on a Si φφ Si substrate which was subjected to steam pretreatment with hexamethyldiazane (HMDS), and prebaked on a hot plate at 105 ° C for 60 seconds. A 40 nm photoresist film was formed. EUV exposure was performed with NA0.3 and dipole illumination. Immediately after the exposure, post-exposure baking (PEB) was performed on a hot plate for 60 seconds, and immersion development was performed for 30 seconds with a 2.38 mass% TMAH aqueous solution to obtain a positive pattern. The obtained photoresist pattern was evaluated in the following manner. The line and pitch of 30 nm were defined as the resolution of the smallest of the 1:1 resolution, and the edge roughness (LWR) of 35 nm LS was measured by SEM. The results of the photoresist composition and the sensitivity and resolution of the EUV exposure are shown in Table 2.

[Table 2] <TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> </td><td> Polymer (parts by mass) </td> <td> Acid generator (parts by mass) </td><td> Basic compound (parts by mass) </td><td> Organic solvent (parts by mass) </td><td> PEB temperature (°C) < /td><td> Sensitivity (mJ/ cm²) </td><td> Resolution (nm) </td><td> LWR (nm) </td></tr> <tr><td> Example 2-1 </td><td> Polymer 7 (100) </td><td> - </td><td> Amine 1 (1.0) </td><td > PGMEA (1,000) CyH(2,000) PGME(500) </td><td> 90 </td><td> 16 </td><td> 22 </td><td> 3.8 </td>< /tr><tr><td> Comparative Example 2-2 </td><td> Comparative Polymer 4 (100) </td><td> - </td><td> Amine 1 (1.0) </ Td><td> PGMEA (1,000) CyH(2,000) PGME(500) </td><td> 90 </td><td> 19 </td><td> 25 </td><td> 5.0 < /td></tr></TBODY></TABLE>

From the results of Tables 1 and 2, it is understood that the photoresist material of the polymer compound obtained by copolymerizing a butyl methacrylate substituted with a third butyl group or a third pentyl group is sufficient. The resolution, sensitivity, and edge roughness, and by further copolymerizing the acid generator, can improve the resolution and edge roughness characteristics.

no.

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Claims (8)

A positive-type photoresist material comprising a repeating unit obtained by substituting a hydrogen atom of a carboxyl group and/or a phenolic hydroxyl group with an acid labile group, and a repeating unit represented by the following formula (1) having a weight average molecular weight of 1,000 a polymer compound in the range of ~500,000 as a base resin; (wherein R ¹ is a hydrogen atom or a methyl group, R ² is a hydrogen atom or a methyl group, and m and n are 1 or 2). A positive-type photoresist material according to the first aspect of the patent application, which is a repeating unit represented by the following general formula (a), and a repeating of the acid-labile group represented by the following general formula (b1) and/or (b2) a polymer compound having a weight average molecular weight of from 1,000 to 500,000 represented by the following formula (2) obtained by copolymerization of a unit as a base resin; (wherein R ¹ , R ² , m, and n are the same as defined above; R ³ and R ⁵ are a hydrogen atom or a methyl group; R ⁴ and R ⁸ represent an acid labile group; and R ⁶ represents a single bond or a carbon number of 1~ a linear or branched alkyl group of 6; R ⁷ represents a hydrogen atom, a fluorine atom, a trifluoromethyl group, a cyano group, or a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms; p is 1 or 2, q is an integer of 0 to 4; Y ₁ is a single bond, a linking group having an ester group, an ether group or a lactone ring having a carbon number of 1 to 12, a stretching phenyl group, or a stretching naphthyl group; ₂ is a single bond, -C(=O)-O-, or -C(=O)-NH-; 0<a<1.0, 0≦b1<1.0, 0≦b2<1.0, 0<b1+b2<1.0, 0.1≦a+b1+b2≦1.0). A positive-type photoresist material according to claim 2, which is a repeating unit b1 in which the repeating unit a in the formula (2) and a hydrogen atom of a carboxyl group and/or a phenolic hydroxyl group are substituted into an acid labile group. And/or b2, and having a selected from the group consisting of a hydroxyl group, a carboxyl group, a lactone ring, a carbonate group, a thiocarbonate group, a carbonyl group, a cyclic acetal group, an ether group, an ester group, a sulfonate group, a cyano group, a decylamine a repeating unit c of a group of -OC(=O)-G- (G is a sulfur atom or NH) (except for repeating units a, b1 and b2) is copolymerized (here, A polymer compound having a weight average molecular weight of from 1,000 to 500,000 in the range of 0 < c ≦ 0.9, 0.2 ≦ a + b1 + b 2 + c ≦ 1.0 is used as a base resin. The positive-type photoresist material of the third aspect of the invention is the repeating unit a, b1, b2, c, and one or more selected from the group consisting of the sulfonium salts d1 to d3 represented by the following general formula (3). The repeating unit is copolymerized (here, 0.2≦a+b1+b2+c<1.0, 0≦d1≦0.5, 0≦d2≦0.5, 0≦d3≦0.5, 0<d1+d2+d3≦0.5, 0.2<a+b1+b2+c+d1+d2+d3≦1.0) A polymer compound having a weight average molecular weight of 1,000 to 500,000 is used as a base resin. [化3] ^{(Wherein, R 20, R 24, R} 28 is a hydrogen atom or a methyl group, R ²¹ is a single bond, phenylene, -OR-, or _{-C (= O) -Y 0 -R-} ; Y 0 is An oxygen atom or NH, R is a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, an extended alkenyl group or a phenyl group, and may also contain a carbonyl group, an ester group, an ether group or a hydroxyl group; R ²² And R ²³ , R ²⁵ , R ²⁶ , R ²⁷ , R ²⁹ , R ³⁰ and R ³¹ are the same or different linear, branched or cyclic alkyl groups having 1 to 12 carbon atoms, and may also contain a carbonyl group, An ester group or an ether group, or an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 20 carbon atoms or a phenylthio group; Z ₀ represents a single bond, a methylene group, an ethyl group, a phenyl group, and a phenyl group. Fluorinated phenyl, -OR ³² -, or -C(=O)-Z ₁ -R ³² -; Z ₁ represents an oxygen atom or NH, and R ³² represents a linear or branched carbon number of 1 to 6. Or cyclic alkyl, alkenyl or phenyl, may also contain a carbonyl, ester, ether or hydroxyl group; M ^- represents a non-nucleophilic relative ion). The positive-type photoresist material according to any one of claims 1 to 4, which is a chemically amplified photoresist material further containing an organic solvent and an acid generator. For example, the positive-type photoresist material of the fifth aspect of the patent application is formed by blending an alkaline compound and/or a surfactant which is an additive. A pattern forming method, comprising the steps of: coating a positive-type photoresist material according to any one of claims 1 to 6 on a substrate; exposing with high-energy rays after heat treatment; and using The developer is developed. The pattern forming method of claim 7, wherein the exposed high energy ray is a KrF excimer laser, an electron beam, or a soft X ray having a wavelength of 3 to 15 nm.